System and method for large scale detection of hazardous materials in the mail or in other objects

ABSTRACT

A system and method that enables early detection of hazardous materials, such as explosives and biological materials, in the early phases of mail handling or processing.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. patent application Ser. No.10/270,987, filed on Oct. 15, 2002, and also claims priority of U.S.Provisional Application 60/330,055, entitled “System for Large ScaleDetection of Hazardous Materials in the Mail or in Other Objects”, filedon Oct. 16, 2001, which is hereby incorporated by reference herein.

BACKGROUND OF THE INVENTION

This invention relates generally to the detection of hazardous material,and, more particularly to the application and sensing of sensitizingagents for early detection of potentially hazardous material associatedwith mail pieces or the delivery of other objects.

Recently there has been increased awareness of the potential forlarge-scale introduction of hazardous materials, that is, eitherexplosives or biological organisms to create chaos or to harm anintended set of victims. Awareness to detection of explosives has led todevelopment of reagents that can be used to detect the presence ofnitroaromatics, organic nitrates, nitramines, inorganic nitrates,chlorates and bromates based explosives (see U.S. Pat. No. 5,480,612,“Kits for Detecting Explosives”, issued to Y. Margalit on Jan. 2, 1996).

Bacterial agents, such as Bacillus anthracis and Closdistrium botilinum,can be used as biological hazardous materials. Detection methods forbacterial agents have been typically time-consuming using techniquessuch as florescent antibody staining (FAST) and enzyme linkedimmunoassay (ELISA). Detection systems have been recently disclosed thatinvolve labeling antibodies with a detectable label where the detectablelabel utilizes fluorescence, chemiluminescence or chromatic change (seeB. L. Mangold et al., international publication WO 01/83561 A2 forInternational Application No. PCT/US01/13648).

Detection methods have also been recently disclosed in the which thesensor is a polymer which has an alterable property, such asfluorescence or electrical conductivity, and the property is altered bya means of association of the polymer with a moiety including a propertyquenching element, a tethering element and a ligand or recognitionelement (see L. Chen et al., international publication WO00/66790 forInternational Application No. PCT/US00/12423 and see D. G. Whitten etal., international publication WO01/85997 A1 for InternationalApplication No. PCT/US01/14702). In this latter method, upon exposure tothe biological agent, the agent can bind to the ligand or recognitionelement causing the moiety (with the bound biological agent) to separatefrom the polymer thereby un-quenching the alterable property. (Therecognition element can be one of, but not restricted to, a chemicalligand, an antibody or antibody fragment, a peptide nucleic acid, or aprotein.) Measurement of the alterable property results in detection ofthe biological agent.

A popular delivery method among the many delivery methods thatterrorists or other criminals utilize to deliver such hazardousmaterials is to utilize the mail to deliver the hazardous material. Inso doing, not only is damage incurred by the intended victims, but alsoby any set of potential victims that may be in a position of handlingsuch objects as the mail during the delivery or distribution process.

As described above, there is currently technology available to lawenforcement organizations to detect the presence of both explosive andbiological threats. Test kits utilizing the above described materialsgenerally require the gathering of a sample and analyzing offline. Todate, however, there is a lack of systems for early detection of suchhazardous material in the early phases of mail handling or processing.Systems currently in place do not deal with detection prior to enteringinto the formal distribution process. Thus, all along the distributionprocess potential non-intended victims are being subjected to hazardousmaterial carried by, for example, letter or package mail.

There is a need for a system and method for early detection of suchhazardous material in the early phases of mail handling or processing.There is also a need for a system and method for early detection of suchhazardous material that can be performed while the mail is beingprocessed.

BRIEF SUMMARY OF THE INVENTION

The system and method of this invention enable early detection of suchhazardous material such as detection in the early phases of mailhandling or processing. The early detection of such hazardous materialutilizing the system and method of this invention can be performed whilethe mail is being processed.

The system of this invention includes two primary elements: anactivation sub-system and a sense and analyze sub-system. The sense andanalyze sub-system performs the following major functions: illuminationand sensing and analysis of the activation results. In one embodiment,the activation sub-system includes a dispensing system and control ofthe dispensing system by the computer system. In that embodiment, theillumination and sensing functions are performed by at least oneradiation source and at least one detector. During operation of theabove embodiment of the system of this invention, a mail piece istransported on a conveyor belt and is placed in the region where thedispensing system can deposit sensitizing agents on the mail piece.After deposition of the sensitizing agents on the mail piece, theradiation source illuminates the mail piece. The interaction of theradiation source with the sensitizing agent is detected by the detector.The output of detector is provided to a computer system where computerreadable code causes a processor to analyze the detector output obtainedfrom the interaction of the output of the radiation source and thesensitizing agent deposited on the mail piece. If the analysis indicatesthat the mail piece possibly contains hazardous materials, the computerreadable code causes the processor to identify the mail piece aspotentially hazardous. The mail piece can then be set aside for furthertesting.

For a better understanding of the present invention, together with otherand further objects thereof, reference is made to the accompanyingdrawings and detailed description and its scope will be pointed out inthe appended claims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a block diagram of an embodiment of the system of thisinvention.

FIG. 2 is a schematic, block representation of an embodiment of thesystem of this invention;

FIG. 3 is a flowchart of an embodiment of the method of this invention;and

FIG. 4 is a top view of a mail piece during processing by a method ofthis invention.

DETAILED DESCRIPTION OF THE INVENTION

A system and method for early detection of such hazardous material inthe early phases of mail or delivery package handling or processing aredisclosed herein below. The early detection of such hazardous materialutilizing the system and method of this invention can be performed whilethe mail or similar delivered object is being processed.

Although the description below is given in reference to a mail piece,the term “mail piece” as used herein refers to any object in a deliverysystem. For example, the same description of this invention applies to apackage in a delivery system, packages being loaded onto a transportsystem and other situations where a package would be handled andtransported.

A block diagram of an embodiment of the system of this invention isshown in FIG. 1 and a schematic, block representation of an embodimentof the system of this invention is shown in FIG. 2.

Referring to FIGS. 1 and 2, the system 110 of this invention includestwo primary elements: an activation sub-system 85 and a sense andanalyze sub-system 100. The sense and analyze sub-system 100 includestwo components: an illumination and sensing component 90 and anactivation results analysis component 95. In the embodiment shown inFIG. 2, the activation sub-system 85 of FIG. 1 includes the dispensingsystem 125 and the control of the dispensing system 125 by means ofcomputer readable code in memory 220 executing in processor 210 ofcomputer system 120. In this embodiment, the illumination and sensingcomponent 90 includes at least one radiation source 105 and at least onedetector 115. The radiation source 105 is controlled by computer 120 andthe detector 115 provides its output to computer 120. The computer 120has, in memory 220, computer readable code that causes processor 210 tocontrol the receiving of the output of the detector 115 and to analyzethe output of detector 115 when activated mail piece 10 is illuminatedby a radiation source 105. The computer 120 also has, in memory 220,computer readable code that causes processor 210 to control theradiation source 105 and the dispensing system 125.

The operation of the above embodiment of the system of this inventioncan be best described in reference to FIGS. 2 and 3. Mail piece 10 istransported on conveyor belt 150, or a similar mail transport system,and is placed in the region where dispensing system 125 can depositsensitizing agents on mail piece 10. For mail processing systems, thetransport could be one of several existing transports, for example, theDelivery Bar Code Sorter or Automated Flats Sorting Machine. Transportsystems, such as conveyor belts and equivalent transport systems, areknown in the art. As the mail piece 10 approaches the dispensing system125, in one embodiment, a location sensing and control system 122, suchas one of the vision systems known in the industrial art, woulddetermine the location and size of the mail piece 10. The location andsize information is provided to computer 120 and stored in memory 220.In one embodiment, computer 120 has, in memory 220, computer readablecode for receiving the output of the location sensing and control systemand for causing the processor 210 to determine the location and size ofthe mail piece 10.

Dispensing system 125 can have a variety of means for depositing thesensitizing agents. The means required are determined by the medium thatcarries the sensitizing agent. For example, if the sensitizing agent isone of the reagents described in U.S. Pat. No. 5,480,612, which isincorporated by reference herein, Reagents A, B, and C, describedtherein, could be deposited using a spray system, a drop dispensingsystem or an ink jet type nozzle and plunger system. All the abovesystems can be controlled so that the deposition occurs at a given timeand at a desired range or loci of positions. (Known techniques, such ascomputer vision or digital imaging, use of fiduciary marks, and closedloop control systems can be used to control the deposition.) Control ofthe dispensing system 125, in one embodiment, occurs via the processor210 in computer 120 operating under computer code embodied in memory220. Deposition of Reagent D of U.S. Pat. No. 5,480,612 requiresconsideration of the acidity of the reagent. (Reagent A of U.S. Pat. No.5,480,612 is an sensitizing agent for the detection of nitroaromaticssuch as TNT; reagent B serves the same function for organic esters ofnitric acid and nitramines, reagent C serves the same function forinorganic nitrates and reagent D for chlorates or bromates.) Similarly,if the molecules described in international publication WO00/66790 forInternational Application No. PCT/US00/12423, in internationalpublication WO01/85997 A1 for International Application No.PCT/US01/14702, or in international publication WO01/66721 A2 forInternational Application No. PCT/US01/07163 (N. Usman et al.) are usedin the sensitizing agents, the molecules can be contained in awater-based, a water/DMSO based solution, a gel or clay base. Thesesolutions could be deposited using a spray system, a drop dispensingsystem or an ink jet type nozzle and plunger system. The clay based orgel based mixtures could be deposited using a wide nozzle and plungersystem. In one embodiment, after deposition, the mail piece 10 wouldappear as shown in FIG. 4, where stripes 310, 320 are obtained bydepositing sensitizing agents for the detection of explosives (such asreagents A, B, C, D of U.S. Pat. No. 5,480,612) and stripes 330, 340,350 are obtained by depositing sensitizing agents for the detection ofbiological agents (such as solutions or suspensions of the moleculesdescribed in international publication WO00/66790, internationalpublication WO01/85997 or international publication WO01/85997 A1).

After deposition, as the mail piece travels along on conveyor belt 150and, after a travel time equal to or greater than the longest activationlatency time for the deposited sensitizing agents has elapsed, thesensitized mail piece 10 approaches illumination and sensing component90. The speed of the conveyor belt could require modulation oradjustment to accommodate the latency time. As the mail piece 10approaches the illumination and sensing component 90, in one embodiment,the location sensing and control system 122, such as one of the visionsystems known in the industrial art, would determine the location of themail piece 10 and the location of stripes 310, 320, 330, 340, 350, ifnecessary.

Still referring to FIG. 2, radiation source 105, under control ofcomputer 120, illuminates the mail piece 10. It should be noted thatradiation source 105 can be more than one radiation source and that theradiation source 105 could include, in one embodiment, an opticalsubsystem (not shown) to focus the beam of radiation. The radiationsource 105 emits the radiation in the wavelength range required toactivate one of the sensitizing agents deposited by dispensing system125. In the embodiment in which one of the sensitizing agents is one ofthe reagents described in U.S. Pat. No. 5,480,612, the requiredradiation source for that sensitizing agent could be ambient light or a“white” light source. In the embodiment in which one of the sensitizingagents is one of the solutions or suspensions of the molecules describedin international publication WO00/66790, international publicationWO01/85997 or international publication WO01/85997 A1, where themolecules are designed to detect a biological agent by a change influorescence or luminescence, the required radiation source for thatsensitizing agent would be a radiation source of a determined wavelengthspectrum. The radiation source 105, in that embodiment, would be a laseror a filtered broad wavelength source and, if needed for sensitivity orto avoid interaction with other sensitizing agents, it would be focusedby an optical system (not shown). It should be noted that it is possibleto select other alterable properties besides those discussed above. Thealterable property can also be, but is not limited to, a change in UVabsorbance, optical rotation, capacitance, or resistance (see, forexample, international publication WO01/66721 A2). The latter alterableproperties require different “radiation” sources. Sensing of UVabsorbance would require a UV source; sensing of optical rotation wouldrequire a radiation source of a predetermined wavelength andpolarization; sensing of capacitance or resistance would require asource of radio frequency (RF) radiation.

The interaction of the radiation source 105 with the sensitizing agentin one of the “stripes” 310, 320, 330,340, or 350 is detected bydetector 115. In the embodiment in which one of the sensitizing agentsis one of the reagents described in U.S. Pat. No. 5,480,612 and thesource of radiation 105 is ambient light or a “white” light source,detector 115 can be one or more CCD or CMOS detectors with colorfilters. The reagents described in U.S. Pat. No. 5,480,612 exhibit achange in color when exposed to a target explosive material. A CCD orCMOS detector with color filters would enable calorimetric detection. Inthe embodiment in which one of the sensitizing agents is one of thesolutions or suspensions of molecules designed to detect a biologicalagent by a change in fluorescence or luminescence, and the radiationsource 105 is laser or a filtered broad wavelength source, detector 115can be one of the detectors described in E. L. Dereniak, D. G. Crowe,Optical Radiation Detectors, ISBN 0-471-89797-3 (1984, John Wiley &Sons). The detector 115, in this embodiment, includes means fordetecting the emitted radiation in a predetermined wavelength band(spectral band). Examples of such means (also referred to as wavelengthseparating means) are filters, including Liquid Crystal Tunable Filters(LCTF) or Acousto-optic Tunable Filters (AOTF) or a holographic gratingor a prism or a polychromator, placed between the emitting mail piece 10and the photo-detecting component of detector 110. Collecting opticscould be used between the wavelength separating means and the emittingsurface. If the alterable property of the sensitizing agent is the UVabsorbance, optical rotation, capacitance, or resistance, detector 115would be a w detector, a polarization sensitive optical detector, or anRF detector or antenna, respectively.

The output of detector 115 is provided to computer system 120. Memory220, a computer usable medium, has computer readable code embodiedtherein that causes processor 210 to analyze the detector outputobtained from the interaction of the output of source 105 and thesensitizing agent deposited on mail piece 10. If the analysis indicatesthat mail piece 10 appears to contain hazardous materials, the computerreadable code causes processor 210 to identify the mail piece 10 aspotentially hazardous. The identification can occur through an outputdevice (not shown) such as a video display unit, a printer or an alarmor a combination of these output devices. In one embodiment, if theanalysis indicates that mail piece 10 potentially contains hazardousmaterials, the computer readable code causes processor 210 to sendsignals to actuator control module 230. Actuator control module 230causes actuator 140 to select mail piece 10, separate it from the streamof mail pieces and set it aside in area 160 for further inspection.

It should be noted that, although the above discussion of an embodimentof this invention describes the operation of the embodiment with aradiation source 105 and a detector 115, several radiation sources andseveral detectors would be used to analyze the response of severalsensitizing agents for the detection of different hazardous materials.

It should also be noted that the term “mail piece” as used herein refersto any object in a delivery system. The term “radiation source” as usedherein applies to any source that provides an output that interacts witha sensitizing agent. “Luminescence” as used herein includesfluorescence.

Each computer readable code within the scope of the claims below may beimplemented in any programming language, such as assembly language,machine language, a high-level procedural programming language, or anobject-oriented programming language. The programming language may be acompiled or interpreted programming language.

Each computer readable code may be implemented in a computer programproduct tangibly embodied in a computer-readable storage device forexecution by a computer processor. Method steps of the invention may beperformed by a computer processor executing a program tangibly embodiedon a computer-readable medium to perform functions of the invention byoperating on input and generating output.

Common forms of computer-readable or usable media include, for example,a floppy disk, a flexible disk, hard disk, magnetic tape, or any othermagnetic medium, a CDROM, any other optical medium, punched cards, papertape, any other physical medium with patterns of holes, a RAM, a PROM,and EPROM, a FLASH-EPROM, any other memory chip or cartridge, a carrierwave, or any other medium from which a computer can read.

Although the invention has been described with respect to variousembodiments, it should be realized this invention is also capable of awide variety of further and other embodiments within the spirit andscope of the appended claims.

1. A method for detection of hazardous materials in a mail piece duringmail handling or processing, said method comprising the steps of:transporting the mail piece on a transport system; depositing at leastone sensitizing agent on a surface of the mail piece while the mailpiece is being transported; transporting said mail piece for apredetermined travel time, said predetermined travel time being equal toor greater than an activation latency time for said at leas onedeposited sensitizing agent on the mail piece, in order to allowactivation prior to reaching sensing means for said at least onesensitizing agent; sensing, while the mail piece is being transported,said at least one sensitizing agent after being deposited on the mailpiece to determine whether hazardous material is located on the surfaceof the mail piece; analyzing results of the sensing to determine whetherthe mail piece possibly contains hazardous materials, wherein a changein a property of the sensitizing agent is indicative of the presence ofthe hazardous materials; and identifying the mail piece as potentiallyhazardous, if said analysis indicates that the mail piece possiblycontains hazardous materials.
 2. The method of claim 1 furthercomprising: performing, if the mail piece is identified as potentiallyhazardous, the further steps of: culling the mail piece; and, settingthe mail piece aside for further inspection.
 3. The method of claim 1wherein said step of depositing comprises applying the sensitizing agentin the form of a solution.
 4. The method of claim 1 wherein said step ofdepositing comprises applying the sensitizing agent in the form of a gelbased agent.
 5. The method of claim 1 wherein said at least onesensitizing agent is a polymer having an alterable luminescence andwherein exposure to a target biological material results in a detectablechange in luminescence.
 6. The method of claim 5 wherein said step ofsensing comprises the steps of: exposing the mail piece to radiation ata first spectrum; and, detecting emitted radiation at a second spectrum.7. The method of claim 1 wherein said at least one sensitizing agent isa reagent and wherein said reagent exhibits a change in color whenexposed to a target explosive material.
 8. The method of claim 7 whereinsaid step of sensing comprises utilizing a detector capable of detectingcalorimetric change.